use wxString argument and not wxChar* in wxHtmlParser::AddText(), for compatibility with STL build without implicit wxString conversions

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@46403 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/html/helpdata.cpp

@@ -125,7 +125,7 @@ public:
     wxObject* GetProduct() { return NULL; }
 
 protected:
-    virtual void AddText(const wxChar* WXUNUSED(txt)) {}
+    virtual void AddText(const wxString& WXUNUSED(txt)) {}
 
     DECLARE_NO_COPY_CLASS(HP_Parser)
 };